Two Questions
1. Would you live in such a society as you describe?
Not by choice, but it wouldn't be awful either. For the common man most of what the nobles are doing is between them. Stirring up the masses occurs rarely and only if conditions are right.
Even then, for most people a civil revolt won't effect every system. The ones with the real political power are the most likely to take the brunt of it.
2. Is this the society that your player have to deal with, or are they all nobles?
If they are a noble they get a pass at things like customs for the most part. But, they are also in the news and the local nobility may
want them to attend state functions, show up for a photo op, or otherwise be inconvenienced with matters of state or business. They make news.
That makes being noble and keeping a low profile difficult. That in turn limits their options to doing things.
Having a noble in the party makes things difficult for the party if they aren't willing to be part of his / her retinue. That is, if he and/or they are acting as equals then it becomes an issue for all of them when they interact with outsiders / NPC. These see a noble with a crew of commoners. The noble's not in charge and not being treated differentially. He's one of the guys so to speak. If that gets out he's now a social pariah in noble circles and treated as such. Where customs before was very hands off now its very hands on. The other nobles start sending a message through secondary means. You act your station or you get smacked down.
On the whole, being a noble is really something I'd think most players would want to avoid in my version of
Traveller. You need means (cash). You need a retinue following you around. For a Knight this might be an executive assistant, maybe a bodyguard. For a Baron or Count, you better have an assistant or three, a bodyguard, maybe a couple of other advisers, a driver for your personal vehicle, and household staff. It goes up from there.
You can't go out and be say a mercenary or a free wheeling trader as a noble. Try it and you end up the equivalent of say a Ronin. You are without respect and lose privilege even as you retain your position.
The view I take is that "Noble" means something real and tangible. It is a vital and important part of who you are. Imperial or not, if you are nobility you
must act the role or face the consequences.
That's distinctly different from a player who is from a noble family but not actually the title holder. Whether that's a bastard child or the fifth child daughter not to inherit, is of no matter. Now you have some social privilege but none of the political and economic responsibilities of the title holder.
You can be the Lieutenant who is an "Officer and Gentleman" who doesn't know who is father really is as the joke goes. But, your are also technically a SOC 10 or less as a result. Being an 11+ means taking on being a noble seriously and having to deal with the consequences of that.
So, my Princess Timerzhan character I put up about a month ago is forced into a station beneath her. How such a character will act is what the game is about. How would you deal with a
Trading Places or
Prince and the Pauper situation? That's how nobility should work. Either you take it seriously and work to maintain your position, or you end up being trampled into the dust by not just nobles but commoners as well.